JPH0441058B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to optical recording media, particularly heat mode optical recording media. Prior Art Optical recording media have the characteristic that the recording medium does not deteriorate due to wear since the medium and the writing or reading head are not in contact with each other, and for this reason, research and development of various optical recording media are being carried out. Among such optical recording media, heat mode optical recording media are being actively developed because they do not require image processing in a darkroom. This heat mode optical recording medium is an optical recording medium that uses recording light as heat. One example is a heat mode optical recording medium that uses recording light such as a laser to melt a part of the medium.
By removing, etc., a small hole called a pit is formed and writing is performed, and information is recorded using this pit.
Some devices perform readout by detecting these pits with readout light. Examples of such pit-forming media include media in which a recording layer made of a light-absorbing dye is formed on a substrate and pits are formed by melting the dye, and media in which pits are formed by melting the dye, and self-oxidizing media such as nitrocellulose. A recording layer containing a thermoplastic resin and a light-absorbing dye is formed, and a recording layer that forms pits by decomposing nitrocellulose, etc. There are also known methods that form pits by melting. When a cyanine dye having an indole ring is used as the dye, it is stable and exhibits an extremely high reflectance, resulting in an extremely high readout S/N ratio. However, in a medium using such a cyanine dye having an indole ring, the dye migrates during storage and may become mixed into the substrate.
Re-agglomeration, recrystallization, or bleed-out may occur, resulting in decreased write sensitivity and read S/S.
There is an inconvenience that the N ratio decreases. In particular, the readout S/N ratio decreases significantly due to high temperature storage after recording. Purpose of the Invention The present invention was made in view of the above-mentioned circumstances, and its main purpose is to provide a cyanine dye having an indole ring that has improved storage stability, especially storage stability at high temperatures after recording. The objective is to provide optical recording media. These objects are achieved by the invention described below. That is, the first invention is characterized by having on a substrate a recording layer made of a dye polymer or a composition thereof made of one or more cyanine dyes having at both ends indole rings to which an aromatic ring may be fused. This is an optical recording medium. Further, a second invention provides a recording layer comprising a dye polymer or a composition thereof comprising one or more cyanine dyes having indole rings at both ends to which an aromatic ring may be fused, and further containing a quencher. An optical recording medium characterized in that it has on a substrate. Specific Configuration of the Invention The specific configuration of the present invention will be described in detail below. The recording layer in the present invention is made of a dye polymer or a composition thereof. In this case, the dye polymer refers to a cyanine dye polymer described below having two or more molecules of one or more types of dye, or a copolymer of the below-described dye and other components. Among these dye polymers,
One or more homocondensates or co-condensates of dyes having one or more functional groups, or one or more dyes having one or more functional groups; Preferably, it is a co-condensate with one or more co-condensate components having one or more functional groups. The condensation reaction for forming such a condensate is preferably one or a combination of two or more of the following condensation reactions involving functional groups. That is, the dye condensate in the present invention is
Two molecules of one or more cyanine dyes are connected via one or more linking groups obtained by the following reactions, or via the linking groups below and the co-condensation component residues described below. It is preferable that the above polymerization is performed. In the following, A represents a dye or a residue of a co-condensed component, R represents hydrogen or a substituted or unsubstituted alkyl group or aryl group, and X represents a halogen. (1) −COOH＋−OH→−COO−＋H ₂ O↑ (2) −COOH＋−NHR→−CONHR−＋H ₂ O↑ (7) −COCl＋−OH→−COO−＋H ₂ O↑ (8) −COCl＋−NH ₂ →−CONH＋H ₂ O↑ (11) −OH+−NCO→−OCONH− (12) −NH ₂ +−NCO→−NHCONH− (14) −NH ₂ +SO ₃ H→−SO ₂ NH−＋H ₂ O↑ (18) −SO ₃ H＋−OH→−SO ₃ −＋H ₂ O↑ (19) −SO ₂ Cl＋−OH→−SO ₃ −＋HCl↑ (20) −SO ₂ Cl＋NH ₂ →−SO ₂ NH−＋HCl↑ (23) -CHO+-NH ₂ →-C=N-+H ₂ O↑ (24) -OCOCl+-NH ₂ →-OCONH-+HCl↑ (25) 2-NHCH ₂ OH+H ₂ NCONH ₂ →-NHCH ₂ NHCONHCH ₂ NH − (26) −CONHNH ₂ +−COCl →−CONHNHCO− ₍ 28 ₎
It is preferable that it has one or more of the functional groups listed in (1) to (28). In this case, in particular, the above (1), (2), (3), (5), (7),
(10), (11), (14), and (19) are preferred. In particular, the functional groups of the dyes and cocondensation components used are -OH, _-NH2 , -COOH, -
COCl, −NCO,

[Formula] One or more of -SO ₂ Cl, an acid anhydride group, and -SO ₃ H, and in particular, the functional group of the dye is preferably -OH, -COOH, and -SO ₃ H. Note that two or more types of functional groups may be added to the dye and the cocondensation component, but considering problems in their synthesis and ease of control of the condensation reaction,
It is preferable that the dye and the cocondensation component have one type of functional group, and it is particularly preferable that the dye has about 2 to 3 functional groups, and the cocondensation component has about 2 to 3 functional groups. In particular, when difunctional compounds are used, a linear polymer is obtained and the thermoplasticity is good, resulting in favorable results. In the combination in which the above condensation reactions (1) to (28) occur, two types of di- to tri-functional, preferably bi-functional dyes are usually used, or a combination of di- to tri-functional, preferably bi-functional dyes is used. A di- to tri-functional, preferably di-functional, co-condensation component is used. . The dye used is a cyanine dye having an indole ring at both ends to which an aromatic ring may be fused. Among such cyanine dyes, those represented by the following formula [] are preferred. Formula [] Φ-L=Ψ (X ^- ) _n In the above formula [], Ψ and Φ represent an indole ring to which an aromatic ring, such as a benzene ring, naphthalene ring, or phenanthrene ring, may be fused. These Φ and Ψ may be the same or different, but are usually the same, and various substituents may be bonded to these rings. In addition,
In Φ, the nitrogen atom in the ring has a positive charge, and in Ψ, the nitrogen atom in the ring is neutral. The skeleton rings of these Φ and Ψ are preferably those represented by the following formulas [Φ] to [Φ]. In addition, in the following, the structure is shown in the form of Φ. In these various rings, the group R ₁ bonded to the nitrogen atom in the ring is a substituted or unsubstituted alkyl group or aryl group. There is no particular restriction on the carbon atom of the group R ₁ bonded to the nitrogen atom in such a ring. Further, it is preferable that this R ₁ group further has a substituent. In this case, the substituent for R ₁ is preferably a functional group such as a sulfone group, a hydroxyl group, or a carboxy group, which may be a metal salt. It may be an amide group, an alkoxyoxy group, an alkylamino group, an alkylcarbamoyl group, an alkylsulfamoyl group, a halogen atom, or the like. Note that when m described below is 0, the group R ₁ bonded to the nitrogen atom in Φ is a substituted alkyl or aryl group and has one charge. Further, the above functional group is preferably included in R ₁ , and is particularly preferably an alkyl group to which a hydroxyl group, a carboxy group, or a sulfone group which may be a metal salt is bonded. Furthermore, two substituents R ₂ and R ₃ are preferably bonded to the 3-position of the indole ring. in this case,
The two substituents R ₂ and R ₃ bonded to the 3-position are preferably an alkyl group or an aryl group. Among these, unsubstituted alkyl groups having 1 or 2 carbon atoms, particularly 1, are preferred. On the other hand, another substituent R ₄ may be bonded to a predetermined position in the ring represented by Φ and Ψ. Such substituents include functional groups such as carboxy groups, as well as various substituents such as alkyl groups, aryl groups, heterocyclic residues, halogen atoms, alkoxy groups, alkylthio groups, alkyloxycarbonyl groups, and alkylcarbonyloxy groups. It can be a base. And the number of these substituents (p, q) is
Usually, it is about 0 or 1 to 4. In addition, p,
When q is 2 or more, the plurality of R _4s are different from each other. On the other hand, L represents a linking group for forming a mono-, di-, tri- or tetracarbocyanine dye, and is particularly preferably one of formulas [L] to [L]. Formula [L] Formula [L] Formula [L] Formula [L] Formula [L] Formula [L] Formula [L] Formula [L] Here, Y represents a hydrogen atom or a monovalent group. In this case, monovalent groups include lower alkyl groups such as methyl groups, lower alkoxy groups such as methoxy groups, dimethylamino groups, diphenylamino groups, methylphenylamino groups, morpholino groups, imidazolidine groups, and ethoxycarbonylpiperazine groups. Preferable examples include di-substituted amino groups such as, alkylcarbonyloxy groups such as acetoxy groups, alkylthio groups such as methylthio groups, cyano groups, nitro groups, and halogen atoms such as Br and Cl. In addition, in these formulas [L] to [L],
Tricarbocyanine linking group, especially formula [L], [L
] is preferred. Furthermore, X ^- is an anion, preferred examples of which are I ^- , Br ^- , ClO ₄ ^- , BF ₄ ^- ,

【formula】

[Formula] etc. can be mentioned. Note that m is 0 or 1, but when m is 0, R ₁ of Φ usually has one charge and becomes an inner salt. Further, it is preferable that the functional group is bonded to the R ₁ . Next, specific examples of the dyes used in the present invention will be given, but the present invention is not limited to these. In addition, in the following, φ represents a phenyl group.

【table】

[Table] These cyanine dyes having an indole ring are
It can be easily synthesized according to known methods. On the other hand, as the co-condensation component, the following are suitable. C1 Dialcohol Ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,
1,10-decanediol, 1,4-cyclohexanediol, p,p'-dihydroxy-2,2
-dicyclohexylpropane, bisphenol A, hydroquinone, p,p'-biphenol,
Hydroquinone dihydroxyethyl ether, polyethylene glycol (n=2-50), etc. C2 Dicarboxylic acids and their acid chlorides Succinic acid, malonic acid, glutanoic acid, adipic acid, pimelic acid, suberic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, etc. Or these acid chlorides. C3 diamine 1,2-diaminoethane, 1,4-diaminobutane, hexamethylenediamine, diaminobenzyl, p,p'-diaminodiphenylmethane,
Diaminodiphenyl sulfide, diaminodiphenylsulfone, 3,3'-dichloro-4,4'-
Diaminodiphenylmethane, diaminodicyclohexylmethane, piperazine, 2,5-dimethylpiperazine, bisaminopropylpiperazine, 4,4'-diaminodiphenyl ether,
3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylmethane, isophorone diamine, etc. C4 di- or triisocyanate 2,4-tolylene diisocyanate, 2,6
- Tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, polymethylene diisocyanate, adduct polyisocyanate, etc. Coronate HL, Coronate AP, Coronate 2030, Coronate L, manufactured by Nippon Polyurethane Co., Ltd.
Demosyur N, Demosyur HL manufactured by Sumitomo Bayer Urethane, Takenate manufactured by Takeda Pharmaceutical Co., Ltd.
Various di- or triisocyanates such as D110N, LDI-100 manufactured by Kyowa Hakko Co., Ltd., and Millionate MS50 manufactured by Nippon Polyurethane Co., Ltd. C5 Diepoxy compound ethylene glycol diglycidyl ether,
propylene glycol diglycidyl ether,
Glycerol polyglycidyl ether, diglycerol polyglycidyl ether, sorbitol polyglycidyl ether, polyethylene glycol glycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6
-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether,
Fatty acid diglycidyl ether, terephthalic acid diglycidyl ether, spiroglycol diglycidyl ether, etc. C6 Acid anhydride Pyromellitic anhydride, phthalic anhydride, trimellitic anhydride, cyclohexanetetracarboxylic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetramethylene maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride acids, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, etc. C7 Dihydrazide Sebacic acid dihydrazide, adipic acid dihydrazide, isophthalic acid dihydrazide, etc. C8 Diiminocarbonate N,N'-p-phenylenebis (ethyleneiminocarbonate), etc. Two of these cyanine dyes with indole rings
One or more types of cyanine dyes, or one or more types of cyanine dyes and one or more types of co-condensed components are separately preliminarily condensed according to a conventional method, and then used after being purified. In some cases, a dye and a co-condensation component may be dissolved separately in a composition liquid for coating the recording layer, and after coating, heating may be applied to cause a condensation reaction. The dye polymer preferably contains about 2 to 20 molecules, particularly about 4 to 10 molecules of the dye. Although the recording layer of the medium of the present invention is made of a polymer of such a dye, the recording layer may contain other resins separately. At this time, coating properties are improved, and recording sensitivity, readout S/N ratio, etc. are improved. Examples of such resins include, for example, Japanese Patent Application No. 1983-
Those described in No. 15229 etc. are suitable. The resin is contained in an amount of about 50% or less by weight based on the dye polymer. Preferably, such a recording layer further contains a quencher. This reduces reproduction deterioration and improves light resistance. Various quenchers can be used as the quencher, but in particular, when the dye is excited and singlet oxygen is generated, it undergoes electron transfer or energy transfer from the singlet oxygen and becomes excited, returns to the ground state by itself, and , is preferably a singlet oxygen quencher that converts singlet oxygen to the triplet state. Various substances can be used as singlet oxygen quenchers, but transition metal chelate compounds are particularly preferred because they reduce regeneration deterioration and have good compatibility with dye polymers. preferable. In this case, the central metal is preferably Ni, Co, Cu, Mn, etc., and the following compounds are particularly preferred. (1) Acetylacetonate chelate system Q1 Ni () acetylacetonate Q2 Cu () acetylacetonate Q3 Mn () acetylacetonate Q4 Co () acetylacetonate (2) Bisdithio-α-diketone system Here, R ⁽¹⁾ to ⁽⁴⁾ represent a substituted or unsubstituted alkyl group or aryl group, and M represents a divalent transition metal atom. In this case, M has a single charge and may form a salt with a quaternary ammonium ion or the like. Q5 Ni()dithiobenzyl Q6 Ni()dithiobiacetyl (3) Bisphenyl dithiol type Here, R ⁽⁵⁾ and R ⁽⁶⁾ represent an alkyl group such as a methyl group, or a halogen atom such as Cl, and M represents a divalent transition metal atom such as Ni. Furthermore, a and b are each 0 or an integer of 4 or less. Further, M in the above structure may have a single charge and form a salt with an anion, and further, other ligands may be bonded above and below M. As such, the following are commercially available. Q10 PA-1001 (product name manufactured by Mitsui Toatsu Fine Co., Ltd.) Q11 PA-1002 [Ni-bis(toluene dithiol) tetra(t-butyl) ammonium as above] Q12 PA-1003 (same as above) Q13 PA-1005 [Ni as above] -bis(dichlorobenzene)tetra(t-butyl)ammonium] Q14 PA-1006 [Ni-bis(trichlorobenzenedithiol)tetra(t-butyl)ammonium] Q15 Co-bis(benzene-1,2-dithiol)tetra Butylammonium Q16 Co-bis(0-xylene-4,5-dithiol)tetra(t-butyl)ammonium Q17 Ni-bis(benzene-1,2-dithiol)tetrabutylammonium Q18 Ni-bis(0-xylene-4 ,5-dithiol)tetrabutylammonium Q19 Ni-bis(5-chlorobenzene-1,2
-dithiol)tetrabutylammonium Q20 Ni-bis(3,4,5,6-tetramethylbenzene-1,2dithiol)tetrabutylammonium Q21 Ni-bis(3,4,5,6-tetrachlorobenzene-1,2 dithiol) tetrabutylammonium (4) dithiocarbamate chelate system Here, R ⁽⁷⁾ and R ⁽⁸⁾ represent an alkyl group. Moreover, M represents a divalent transition metal atom. Q22 Ni-bis(dibutyl dithiocarbamic acid) [Antigen NBC (manufactured by Sumitomo Chemical)] (5) Bisphenylthiol type Q23 Ni-bis(octyl phenyl) sulfide (6) Thiocatechol chelate type Here, M represents a divalent transition metal atom.
Further, M has a single charge and may form a salt with an anion, and the benzene ring may have a substituent. Q24 Ni-bis(thiocatechol)tetrabutyl ammonium salt (7) Salicylaldehyde oxime type Here, R ⁽⁹⁾ and R ⁽¹⁰⁾ represent an alkyl group, and M represents a divalent transition metal atom. Q25 Ni()0-(N-isopropylformimidoyl)phenol Q26 Ni()0-(N-dodecylformimidoyl)phenol Q27 Co()0-(N-dodecylformimidoyl)phenol Q28 Co()0 -(N-dodecylformimidoyl)phenol Q29 Ni()2,2'-[ethylenebis(nitrilomethylidine)]-diphenol Q30 Co()2,2'-[ethylenebis(nitrilomethylidine)]-diphenol Q31 Ni()2,2′-[1,8-naphthylenebis)nitrilomethylidine)]-diphenol Q32 Ni()-(N-phenylformimidoyl)phenol Q33 Co()-(N-phenylformimide yl)phenol Q34 Cu()-(N-phenylformimidoyl)phenol Q35 Ni()salicylaldehyde phenylhydrazone Q36 Ni()salicylaldehyde oxime(8) Thiobisphenolate chelate system Here, M is the same as above, R ⁽¹¹⁾ and
R ⁽¹²⁾ represents an alkyl group. Further, M has one charge and may form a salt with an anion. Q37 Ni()n-butylamino[2,2'-thiobis(4-tert-octyl)-phenolate][Cyasorb-UV-1084 (American Cyanamide Co., Ltd.)] Q38 Co()n-butylamino[ 2,2'-thiobis(4-tert-octyl)-phenolate] Q39 Ni()-2,2'-thiobis(4-tert-octyl)-phenolate (9) Phosphonous acid chelate system Here, M is the same as above, R ⁽¹³⁾ and
R ⁽¹⁴⁾ represents a substituent such as an alkyl group or a hydroxyl group. In addition, other quenchers include the following. (10) Benzoate Q51 Existing chemical substance 3-3040 [Tinuvin-120
(manufactured by Ciba Geigy)] (11) Hindered amine Q52 Existing chemical substance 5-3732 [SANOLLS-770
(manufactured by Sankyo Pharmaceutical Co., Ltd.)] Such a quencher is synthesized according to a known method. The quencher is generally 0.05 to 12 mol, especially 0.05 to 12 mol per mol of the dye in the dye polymer.
It is contained in an amount of about 0.1 to 1.2 moles. Note that the maximum absorption wavelength of the quencher is preferably greater than or equal to the maximum absorption wavelength of the dye used. As a result, reproduction deterioration becomes extremely small. In this case, the difference between the two is preferably 0 or 350 nm or less. In order to form such a recording layer, it is generally necessary to apply the coating according to a conventional method, and the thickness thereof is generally as follows.
It is set to 0.03 to 100 μm. The thickness of the recording layer is usually 0.03 to 10 μm.
It is considered to be a degree. In addition, such a recording layer may contain other polymers or oligomers, various plasticizers, surfactants, antistatic agents, lubricants, flame retardants, stabilizers, dispersants, crosslinking agents, etc. Good too. To deposit such a recording layer, on the substrate,
What is necessary is just to apply|coat using a predetermined solvent and to dry. Examples of solvents used for coating include ketones such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, esters such as butyl acetate, ethyl acetate, carbitol acetate, and butyl carbitol acetate, and ethers such as methyl cellosolve and ethyl cellosolve. , aromatic systems such as toluene and xylene, halogenated alkyl systems such as dichloroethane, and alcohol systems. The material of the substrate on which such a recording layer is provided is not particularly limited, and may be any of various resins, glass, ceramics, metals, etc. Further, its shape may be a tape disk, a drum, a belt, etc. depending on the intended use. Note that the base body usually has a tracking groove. Further, if necessary, it may have a base layer such as a reflective layer, a heat storage layer, a light absorption layer, etc. Further, as the substrate material, a substrate without grooves, such as acrylic resin, epoxy resin, polycarbonate resin, polysulfone resin, polyethersulfone, methylpentene polymer, etc., is suitable. These substrates can also be coated with a primer to improve solvent resistance, wettability, surface tension, thermal conductivity, etc. As the primer, for example, titanium-based, silane-based, or aluminum-based coupling agents, various photosensitive resins, etc. can be used. Further, on the recording layer, a reflective layer that functions as a back surface when a transparent substrate is used, various uppermost protective layers, a half mirror layer, etc. can be provided as necessary. The medium of the present invention may have the recording layer described above on one surface of such a substrate, or may have recording layers on both surfaces thereof. Also,
Two substrates with recording layers coated on one side are used, and the recording layers are placed facing each other with a predetermined gap between them, and they are sealed to prevent dust and scratches. You can also do it like this. Specific effects of the invention When the medium of the present invention is running or rotating,
Recording light is irradiated in a pulsed manner. At this time, the dye polymer and thermoplastic resin in the recording layer are melted by heat generation, and pits are formed. The pits thus formed are read out by detecting the reflected or transmitted light of the readout light, particularly the reflected light, while the medium is running or rotating. In this case, recording and reading are preferably performed from the base side, but may also be performed from the recording layer side. It is also possible to erase the pits once formed in the recording layer with light or heat and rewrite. Note that the recording or reading light can be a semiconductor laser, He-Ne laser, Ar laser, He
-Cd laser etc. can be used. Specific Effects of the Invention According to the present invention, even if the medium is stored for a long time,
There is very little deterioration in writing sensitivity or S/N ratio. In particular, the deterioration of the S/N ratio when read after recording and storage at a high temperature is extremely small. Furthermore, since a cyanine dye having an indole ring is used, the reflectance is high and the readout S/N ratio is also extremely high. In addition, according to the second invention, reproduction deterioration is significantly reduced and light resistance is extremely high. The present inventors conducted various experiments to confirm the effects of the present invention. An example is shown below. Experimental Example 1 Using the above cyanine dyes D6 and D10 and the following co-condensation components M and N, a dye polymer was synthesized by equimolar condensation. Both of these are IR
As a result of thin layer chromatography measurement, it was confirmed that a polymer was formed. This polymer was dissolved in dichloroethane and layered to a thickness of 0.07 μm on a polymethyl methacrylate substrate having tracking grooves to form a recording layer. Further, the following resins R1 and R2 were added to these recording layers at a weight ratio of 20% based on the polymer to form recording layers. Apart from this, for comparison, the following dyes D6 and D10
A recording layer was formed in which dye Q14, shown as a quencher, and resins R1 and R2 were added in a weight ratio of 7:3. The dyes, cocondensation components, and resins used are as follows. Cocondensation component A Adipic acid cocondensation component B Hexamethylenediamine cocondensation component C 1,6-hexanediol resin R1 α-methylstyrene (number average molecular weight 1
10,000) Resin R2 Polymethyl methacrylate (number average molecular weight 10,000) For each sample prepared in this way,
While rotating at 1800 rpm, a semiconductor laser (830 nm) was focused on a diameter of 1 μm from the back side of the substrate (output of the focusing section was 10 mW), and writing was performed with a pulse width of 100 nsec. After this, a 1mW semiconductor laser readout light is applied.
A 1 μsec width, 3 KHz pulse was irradiated from the back side of the substrate, and the reflected light was detected to measure the C/N ratio. Next, each sample was stored at 50° C. and 90% relative humidity for 1000 hours, and then the deterioration of the C/N ratio was measured. Table 1 shows the deterioration rate (%) of the C/N ratio after storage.

【table】

[Table] From the results shown in Table 1, the effects of the present invention are clear. Experimental Example 2 Sample 25 was obtained by adding Quencher Q14 in a weight ratio of 50% to the dye polymer in Sample No. 2 of Experimental Example 1. 1mW, 1μsec, 300Hz for samples No.2 and No.25
Table 2 shows the reproduction deterioration rate (%) of the C/N ratio after irradiation with the readout laser beam for 4 minutes.

[Table] From the results shown in Table 2, the effect of the second invention is clear.

Claims (1)

[Scope of Claims] 1. It is characterized by having on a substrate a recording layer made of a dye polymer or a composition thereof made of one or more cyanine dyes having indole rings at both ends to which an aromatic ring may be fused. optical recording medium. 2. The optical recording medium according to claim 1, wherein the dye polymer is a homocondensate or a cocondensate of one or more cyanine dyes. 3. The optical recording medium according to claim 1 or 2, wherein the recording layer comprises a dye polymer composition containing a dye polymer and a resin. 4. Having a recording layer on the substrate, which is made of a dye polymer or a composition thereof consisting of one or more cyanine dyes having indole rings at both ends to which an aromatic ring may be fused, and further containing a quencher. An optical recording medium characterized by: 5. The optical recording medium according to claim 4, wherein the dye polymer is a homocondensate or co-condensate of one or more cyanine dyes. 6. The optical recording medium according to claim 4 or 5, wherein the recording layer is made of a dye polymer composition containing a dye polymer and a resin. 7. The optical recording medium according to any one of claims 4 to 6, wherein the quencher is a transition metal chelate compound. 8. The optical recording medium according to claim 4, wherein the maximum absorption wavelength of the quencher is greater than or equal to the maximum absorption wavelength of the cyanine dye.